Two New Isoflavones from Pueraria lobata and Their Bioactivities

摘要

Two new isoflavones, 4′,6-dimethoxy-8-hydroxy-7-hydroxymethylisoflavone ( 1 ) and 4′,8-dihydroxy-7-hydroxymethyl-6-methoxyisoflavone ( 2 ), together with three known isoflavones ( 3–5 ), were isolated from Pueraria lobata. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–5 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 2 exhibited high anti-TMV activity with inhibition rates of 32.6%. The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 21.4–25.3%, respectively. The cytotoxic activity of compounds 1–5 against five human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) was also tested. The results revealed that compounds 1–5 showed weak inhibitory activities against some human tumor cell lines, with IC~(50)values in the range of 6.9–9.8 μM.